Solar water heating system

ABSTRACT

One or more hot water solar systems or solar collection assemblies are disclosed herein. The solar collection assemblies may include an insulating support assembly for supporting a tank above a nearby ground surface. An immersion vent having improved characteristics may be provided. A BTU meter positioned within an equipment cavity and having improved characteristics may be provided. Insulated tank supports having improved characteristics may be provided. A heat exchanger to panel sizing ratio for improved performance may be provided.

This application claims priority to U.S. Provisional Patent Application No. 61/570,119 entitled “SOLAR WATER HEATING SYSTEM” that was filed on Dec. 13, 2011, the entire contents of which are hereby incorporated by reference.

BACKGROUND

Conventional equipment for commercial water heating consists of many separate components assembled on site into a system. The components typically include a boiler or water heater, with an insulated tank to preserve the heat stored therein. Alternatively, the boiler and hot water storage tank may be separate units. Other components for generating, controlling, and distributing the heated water include pumps, valves, site gauges, temperature sensors, flow sensors, heat exchangers and others which are usually not insulated, or only partially insulated, causing a significant loss of heat from the system. It has been customary to oversize the boiler or water heater capacity to compensate for these losses.

In addition, conventional hot water storage tanks typically have uninsulated ports and mounting bases, and various uninsulated fittings and gauges. The heat loss and inefficiency are great which means a large amount of energy is wasted. Most equipment rooms are very hot due to the excessive heat lost from hot water system components.

Solar power has also provided energy to heat water. This energy source may involve complex systems to efficiently harness and store energy from the sun. Specifically, solar power requires an array of solar collectors to capture the rays of the sun and heat water. A fluid such as water may be used to transport the solar energy from the collector to a storage tank. The solar heated fluid may be used directly as hot water, or used to heat portable water through a heat exchanger. Whatever the manner of creating solar hot water, a key consideration in any system is the transport, storage, and control of heated liquids.

Solar water heating systems convert sunlight into thermal energy to heat water. Excessive heat may be wasted by the system through uninsulated or poorly insulated components. Likewise, there are different solar system designs that have different levels of wasteful components. Systems using antifreeze and pressurized storage tanks are an example of a wasteful system. These systems require pressure relief valves, heat exchangers between the collectors and tank, check valves, expansion tanks, air vents, heat dumps, and other components that are usually field installed and may be uninsulated or only partially insulated.

Several controls in a variety of materials and configurations are required to run the system. Their purpose is not to decrease the heat loss, and may actually contribute to wasted energy. Hot fluids going through the components from the collectors to the storage tank to the load will lose heat to the surroundings when these components are not insulated and are exposed to the ambient air. These components may be a significant source of heat loss. Some of the components cannot be insulated, such as some air cooled motors, however, other components may not be insulated because it is difficult or inconvenient to do so.

Vents are also used to maintain atmospheric pressure equilibrium in non-pressurized systems, but these vents are designed in a manner which results in heat loss as well as evaporation of the liquid.

In one drainback solar system design, the heat lost from the components above is almost completely eliminated, resulting in the highest thermal efficiency possible. This application describes designs and methods for integrating all the components of a drainback solar system into one integrated, factory assembled package that contains the storage tank and heat losing and heat generating components inside one insulating shell. This system also minimizes the heat wasted through typical tank mounting systems.

Thus, there has not been an effective device or system for efficiently transferring and storing heated liquids. Accordingly, it is desirable to provide a device for the effective storage of heated liquids coupled with insulated components that can store and transfer heated liquids without the loss of heat or liquid volume due to static evaporation losses while addressing the limitations of the conventional devices.

SUMMARY

The Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description of Illustrative Embodiments. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Disclosed herein is a solar hot water system. The system includes a collector system for receiving thermal energy from the sun and a fluid handling system in communication therewith and including a storage tank and a heat exchanger configured for converting thermal energy from the collector system into heating energy for heating a water source.

According to one or more embodiments, the insulation on the storage tank is extended to form a cavity into which operating components can be placed, thereby eliminating or minimizing their heat loss, or effectively capturing their heat gain.

According to one or more embodiments, an immersion vent is defined in the storage tank and extending from a sidewall thereof at an angle into a top portion of the tank.

According to one or more embodiments, the system may include heat losing components such as heat exchangers, site glasses, valves, thermal wells, piping, and other components positioned within the insulated cavity defined in the tank.

According to one or more embodiments, the system may include heat generating components such as pumps, BTU meters, and other electrical and heat producing devices positioned within the insulated cavity defined in the tank.

According to one or more embodiments, the system includes one or more supports for supporting the tank on a ground surface, the supports having insulative properties for insulating the tank from the ground surface. Some jurisdictions do not allow materials that are not fireproof, such as wood, unless specially treated with a fire retardant. Non conducting structural materials such as polymers may be used in lieu of wood. However, metal skids welded directly to the tank cause severe heat loss from the tank.

According to one or more embodiments, a solar collection assembly is provided. The assembly includes an array configured for receiving energy from sunlight and passing a fluid therethrough to heat the fluid, a tank assembly in fluid communication with the array and configured for storing heated fluids, and an insulated support that carries the tank assembly spaced-apart from a surrounding surface.

According to one or more embodiments, the support includes a skid that runs about the length of the tank assembly and the skid is made from an insulating material.

According to one or more embodiments, the support includes supports that define a joint about a medial portion, the joint defining a gap that receives a block of insulating material.

According to one or more embodiments, the solar collection assembly includes an immersion vent defined in a storage tank of the tank assembly and extending from a sidewall thereof at an angle into a top portion of the tank.

According to one or more embodiments, the tank assembly includes a tank that is receivably enclosed within an insulated casing, the tank having a length shorter than the casing to thereby define an insulated cavity therein.

According to one or more embodiments, a line extends from the tank through the insulated cavity outward of the tank assembly for supplying liquid to the array.

According to one or more embodiments, the solar collection assembly further includes a pump positioned outward of the tank assembly and in communication with the line for pumping liquids to the array.

According to one or more embodiments, one or more heat generating components are positioned within the insulated cavity.

According to one or more embodiments, the one or more heat generating components are one of a heat exchange, pump, and flow sensor.

According to one or more embodiments, a tank assembly for use with a solar collection assembly is provided. The tank assembly includes a casing defining an inner insulating layer and an insulated cavity therein, a tank that is received within the insulated cavity, and an insulated support that carries the tank assembly spaced-apart from a surrounding surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing Summary, as well as the following Detailed Description of various embodiments, is better understood when read in conjunction with the appended drawings. For the purposes of illustration, there is shown in the drawings exemplary embodiments; however, the presently disclosed invention is not limited to the specific methods and instrumentalities disclosed. In the drawings:

FIG. 1 illustrates a schematic view of a single pass drainback system according to one or more embodiments disclosed herein;

FIG. 2 illustrates a storage tank with an insulated cavity according to one or more embodiments disclosed herein;

FIG. 3 illustrates the storage tank of FIG. 2 with an insulated cavity and immersion vent according to one or more embodiments disclosed herein;

FIG. 4 illustrates the storage tank of FIG. 3 with non-conducting tank supports according to one or more embodiments disclosed herein;

FIG. 5 illustrates the storage tank of FIG. 4 with heat losing and heat producing components inside the insulated cavity according to one or more embodiments disclosed herein;

FIG. 6 is a drawing of a fluid handling system showing the embodiments of the previous drawings and showing the placement of pumps outside the cavity;

FIG. 7 illustrates a perspective view of a cylindrical tank with conducting support skids and having a thermal break between the skid and tank according to one or more embodiments disclosed herein;

FIGS. 8A, 8B, and 8C show a detailed view of the thermal break components of FIG. 7;

FIG. 9 illustrates a rectangular tank with non-conducting skids according to one or more embodiments disclosed herein;

FIG. 10 illustrates a rectangular tank with conducting skids with a thermal break between the skid and tank according to one or more embodiments disclosed herein; and

FIGS. 11A and 11B illustrate one or more methods for fastening conducting skids through a thermal break to a rectangular tank according to one or more embodiments disclosed herein.

DETAILED DESCRIPTION

This disclosure is described with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventor has contemplated that the claimed inventions might also be embodied in other ways, to include different steps or elements similar to the ones described in this document, in conjunction with other present or future technologies.

Disclosed herein are one or more storage tanks and associated control components for transfer and storage of heated liquids.

FIG. 1 illustrates a schematic view of a single pass drainback solar system 100. When operational, fluid travels up the supply line 302 via a collector pump 324 and passes through a solar collector assembly 200 where the fluid becomes heated by the energy of the sun. The collector assembly 200 may include an array of solar panels, as illustrated. The collector assembly 200 is in communication with a tank assembly 300. The heated fluid travels down the return line 304 where it is stored in the non-pressurized solar storage tank 306. When the system is not operational, the fluid flows via gravity down the supply line 302 and the return line 304 into the storage tank 306, where the fluid resides until the system is activated again. Various valves and/or switches may also be provided with the system and designated 323.

Simultaneously, domestic cold water (DCW) 1 may be circulated through the heat exchanger 318 which resides submerged within the storage tank 306. DCW 1 is warmed as it passes through the heat exchanger 318 by the heated fluid within the storage tank 306. The warmed DCW 1 flows from the heat exchanger 318 to a domestic hot water heater (DHW heater) 500 where it may be boosted to the final output temperature as needed, and made available for use. A flow sensor 322 monitors the flow of water through the heat exchanger 318 to the DHW heater 500 to provide information to the owner about the amount of energy delivered by the solar system.

FIG. 2 illustrates an exploded side view of tank assembly 300. Tank assembly 300 includes tank 306. Tank 306 may be made of any appropriate material, such as metal, plastic, or composite, and may take on a cylindrical shape as illustrated, or any other desired shape. An insulation layer 310, also referred herein as an insulated casing, extends around the periphery of tank 306. The insulation may be foam or mineral wool or fiberglass as is common in the industry for hot water storage. A sheet metal covering or jacket may be provided over the insulation for protection. Additionally, the insulation layer 310 extends beyond the tank 306, meaning the insulation layer 310 is longer than the tank 306. An insulated door or covering 312 is provided about an end of the tank 306 and enclosed the tank 306 to define an insulated cavity 311 between an end of the tank 306 and the door or covering 312. In this manner, the insulated cavity 311 is insulated on all sides by the insulation layer 310, door or covering 312, and tank 306. In normal operation, the water level 314 in the tank is below the top, creating an air gap 317 between the water surface and the top of the tank.

FIG. 3 illustrates the system of FIG. 2 with the addition of an immersion vent 315 that extends from the air gap 317 in the tank 306 downward through the tank face and out of the insulated cavity 311 to the outside to the ambient. When the system 100 is not in operation, such as at night, or when temperature considerations are satisfied, the air inside the vent pipe 315 has the same temperature gradient as the water in the tank 306, thus tending to rise in the pipe. This action prevents transmission of air and moisture downward through the pipe 315 causing loss of moisture from the tank 306 by evaporation. When the system 100 is operating and the water in the tank 306 is being circulated to the collectors, thus lowering the fluid level, and when the temperature of the water and air is increasing, the vent 315 allows the volume increase in the air to be vented to the atmosphere. The vent 315 also allows the escape of any steam that may be generated in the collectors 200.

As illustrated in FIG. 4, the tank assembly 300 may further include an insulative support system 316 that does not conduct the tank heat to the surrounding floor. FIG. 5 illustrates the system of FIG. 4 with the installation inside the insulated cavity 311 of various heat losing components, including valves 319, piping, site glass 320, temperature sensor wells, and heat exchanger 321 that are not usually insulated in common systems. In use, door or cover 312 would not be spaced-apart from the insulation layer 310 and would seal the tank 306 within the insulation layer 310, thereby enclosing the various heat losing components within the tank insulated cavity 311. In this manner, the one or more embodiments of FIG. 5 show installation inside the insulated cavity 311 of heat generating components, such as pumps 324 and other electrical or otherwise heat generating components such as a flow sensor 325. This arrangement allows for the recapture of heat from the heat generating components within the tank assembly 300 to thereby provide heat to the tank 306 to heat the fluids contained therein.

FIG. 6 shows a perspective view of a tank assembly 300 where collector pumps 324 cannot be used inside the tank cavity 311 due to temperature limitations and are mounted outside the cavity 311, but on fittings 326 that originate inside the cavity. In this embodiment, the collector pumps 324 are unable to safely function within the heated environment in the insulated cavity 311 and are installed outwardly of the tank 306, yet within the insulated cavity.

FIG. 7 illustrates a perspective view of a cylindrical tank with a mounting bracket 8 and conducting skid 328 with an insulative layer 350 introduced in a support leg 330 to prevent thermal conduction from the tank 306 to the skid 328. The insulating layer 350 can be any material known to have high compressive strength and low thermal conductivity, including refractory boards and various fiber impregnated plastics. Fastening the conductive skid to the conductive tank without causing thermal short circuits may be done by having opposing bolts whose heads are countersunk into the insulative material 350 to a depth that prevents contact with the metal part adjacent to the bolt head. While a skid assembly is illustrated, any support system may be used with the one or more embodiments illustrated herein.

FIGS. 8A, 8B, and 8C show a detailed close up of the insulative structure of FIG. 7. The insulating block 350 has countersunk holes to fit fasteners pointing in opposite directions. FIG. 8B shows the bolt arrangement. The upper bolt 354 would be installed first to the tank mounting bracket 8, then the skid with mounting post 355 would be positioned and the lower bolts 353 installed. The nuts for bolts 353 would be pressed into the respective countersunk holes 351 which could be a tight fit to hold the nuts in place. The countersunk holes prevent any bolt from contacting the lower plate and the tank mounting bracket at the same time. FIG. 8C is a side view center cross section of FIG. 8B, illustrating the tank and mounting bracket relationship. The one or more embodiments illustrated in FIGS. 8A, 8B, and 8C are intended to be illustrative only, as many different mounting and fastening methods would accomplish the same function of thermally insulating the skid from the tank.

FIG. 9 illustrates a tank assembly 400 that may include a rectangular tank 406 with non-conducting skids 432 according to one or more embodiments disclosed herein. The tank 406 shares many features with cylindrical tank 306 as also described herein. The non-conducting skids 432 may be any appropriately configured not-conducting, or insulating material. The tank assembly 400 may include an insulating layer 410 that, in conjunction with door or covering 412, defines an insulated cavity 411.

FIG. 10 illustrates that conducting skids 433 may be used in conjunction with an insulating layer 450 known to have high compressive strength and low thermal conductivity, such as refractory boards, various fiber impregnated plastics, and others that may be used between the tank surface and the skid surface. The insulating layer 450 may be interposed between the bottom of the tank and the skid and may be fastened in a manner that does not thermally connect the tank with the skid.

FIG. 11A illustrates the insulating layer having counter-sunk holes 436 in the insulator 450 to allow opposing bolts to be inserted without the heads touching metal. The insulator 450 is bolted to the skid 433, which is then bolted to the threaded nut plate 438 welded on the tank. Bolt access holes 455 on the top of the skid allow the bolts to be inserted through the skid without contacting the skid metal. FIG. 11B illustrates various skid structures, including skids made of angle metal 460, and pipe and angle 461. In any case, the insulation prevents the transfer of heat from the tank to the support.

As used herein, support may be any of a skid, mount, base plate, upright, or the like. Any structure capable of positioning and support of the one or more tanks and systems described herein may be provided.

While the embodiments have been described in connection with one or more embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the one or more embodiments for performing the same function without deviation therefrom. Therefore, the one or more embodiments disclosed herein should not be limited to any single embodiment, but rather construed in breath and scope in accordance with the appended claims. 

I claim:
 1. A solar collection assembly comprising: an array configured for receiving energy from sunlight and passing a fluid therethrough to heat the fluid; a tank assembly in fluid communication with the array and configured for storing heated fluids; and an insulated support assembly that carries the tank assembly spaced-apart from a surrounding surface.
 2. The assembly of claim 1, wherein the support assembly comprises a skid that runs about the length of the tank assembly and the skid is made from an insulating material.
 3. The assembly of claim 1, wherein the support assembly comprises supports that define a joint about a medial portion, the joint defining a gap that receives a block of insulating material.
 4. The assembly of claim 1, further including an immersion vent defined in a storage tank of the tank assembly and extending from a sidewall thereof at an angle into a top portion of the tank.
 5. The assembly of claim 1, wherein the tank assembly includes a tank that is receivably enclosed within an insulated casing, the tank having a length shorter than the casing to thereby define an insulated cavity therein.
 6. The assembly of claim 5, wherein a line extends from the tank through the insulated cavity outward of the tank assembly for supplying liquid to the array.
 7. The assembly of claim 6, further including a pump positioned outward of the tank assembly and in communication with the line for pumping liquids to the array.
 8. The assembly of claim 6, wherein one or more heat generating components are positioned within the insulated cavity.
 9. The assembly of claim 8, wherein the one or more heat generating components are one of a heat exchange, pump, and flow sensor.
 10. A tank assembly for use with a solar collection assembly, the tank assembly comprising: a casing defining an inner insulating layer and an insulated cavity therein; a tank that is received within the insulated cavity; and an insulated support assembly that carries the tank assembly spaced-apart from a surrounding surface.
 11. The assembly of claim 10, wherein the support assembly comprises a skid that runs about the length of the tank assembly and the skid is made from an insulating material.
 12. The assembly of claim 10, wherein the support assembly comprises supports that define a joint about a medial portion, the joint defining a gap that receives a block of insulating material.
 13. The assembly of claim 10, further including an immersion vent defined in a storage tank of the tank assembly and extending from a sidewall thereof at an angle into a top portion of the tank.
 14. The assembly of claim 10, wherein a line extends from the tank through the insulated cavity outward of the tank assembly for supplying liquid to an array.
 15. The assembly of claim 14, wherein one or more heat generating components are positioned within the insulated cavity.
 16. The assembly of claim 14, wherein the one or more heat generating components are one of a heat exchange, pump, and flow sensor. 